This researchproject will permit the investigators to continue studies of the pathophysiology of surgical vascular disorders. Studies of the relative roles of mechanical and humoral factors in initiating the acute changes of pulmonary embolism are continuing. Special studies of the effects ofmultiple humoral agents on the changes are planned. Studies of fluid transport in experimental lymphedema will continue. Ourstudies indicate that lymph formation in lymphedema is not stagnant, but that lymph turnover occurs at signiicant rates. Studies are underway to evaluate mchanisms for increasing rates of lymph flow. The role of the fibrinolytic mechanism in maintaining and restoring vessel patency is being evaluated in the venous system. Studies are being performed on the interaction of platelet factor 4 and heparin in postoperative patients.